text: In cases of such egregious crimes, the host country will revoke the diplomat's status, and begin negotiations with the diplomat's country on how to resolve the situation. Depending on the relationship between the two countries, the diplomat's country may allow the host nation to prosecute the individual. Or they may recall the diplomat and charge them at home. Or they may do nothing, but that might cause the host nation to levy sanctions against them. In any case, since the diplomat's status is revoked, they may not legally remain in the host nation or conduct any official business there, which means they will either be confined to their embassy, or they must leave. If they step out of their embassy without official protection, they become illegal immigrants and will be arrested (but they won't be charged for the original crime, just for being an illegal immigrant.) Source: my father was a diplomat and ambassador.